Joliet, IL Environmental Rules: Erosion Control (2026)

Joliet's erosion and sediment control standard for floodway construction lives in Section 8-507, the article governing occupation and use of identified floodways within Chapter 8's flood damage prevention rules. Subsection (5)k requires that for any grading, filling, or excavation in the floodway where exposed soil could erode, the developer minimize the construction area, schedule work to limit how long soil sits exposed, and never disturb existing natural vegetation more than 15 days before starting improvements. Denuded ground must get temporary or permanent stabilization within 15 days of reaching final grade, and the same 15-day stabilization deadline applies to any denuded area that won't be at final grade but will otherwise sit undisturbed for more than 60 days.

Sediment control, using devices such as filter fences, straw bale fences, check dams, diversion ditches, or sediment traps and basins, has to be installed before any significant grading or filling starts so eroded material can't leave the site or reach the channel. The same subsection calls for a vegetated buffer strip of at least 25 feet along existing channels where practical and ties the whole standard to the "Procedures and Standards for Urban Soil Erosion and Sedimentation Control in Illinois" (the 1988 "Green Book") and the Illinois Urban Manual.

Because this standard sits inside the floodway article, it applies to work within the mapped regulatory floodway rather than every construction site citywide; those developments also need the floodway development permit required elsewhere in the same article. Joliet's floodway maps cover both counties the city spans: Section 8-514 ratifies FEMA's flood insurance rate map effective February 15, 2019, for the Will County portion of the city and the January 8, 2014 panels for the Kendall County portion.